Card Range To Study

22 Cards in this Set

The process of slowly cooling a finished glass object to room temperature. This allows stresses in the glass to be released.

Batch

The mixture of soda, lime and silica, with any colouring agents, which produce glass when fused at high temperatures.

Bezel

That part of the finger ring which bears the design, or into which the stone is set.

Cane

Used to mean a thin rod of glass. Cane and rod are sometimes used interchangeably.

Conglomerate glass

Glass vessels made up from fragments of different coloured glass fused together in a mould. The fragments are usually angular. Since the pieces could, at least in theory, include pieces of cane or rod then the technique is a type of mosiac glass.

Core

A shape, made in mud and/or dung, around which early glass vessels were formed. The friable core was removed on completion of the vessel.

Egyptian blue

Calcium-copper tetrasilicate, a specific type of frit used as a pigment or sometimes in the making of objects or vessels.

Frit

The product of fritting. Frit may be ground for use as a pigment, used for the manufacture of objects, or melted for use in glass making.

Fritting

The first stage in the making of ancient glass, involving a solid state reaction between quartz, lime and plant ash. The product of this process is frit.

Gather

Also known as 'gob'. Literally the viscous molten glass gatehred from the kiln on the end of a metal rod or blowpipe ready for working.

Lentoid

A shape reminiscent of a lentil. The term is commonly used when describing the vessel form also known as pilgrim flask, namely a vessel circular in elevation but oval in plan.

Marver

A flat surface on which vessels are rolled during manufacture in order to make the surface smooth, assist in shaping, and sometime to impress (marver-in) decoration.

Metal

A confusing and inaccurate term sometimes used to refer to substance glass. Fabric is a more appropriate term.

Millefiori glass

Used here to refer to glass vessels made from sections of glass canes fused together in a mould, for example the yellow eyes on a green ground found in the Late Period. Strictly it is a type of mosiac glass. The term meaning 'thousand flowers', is strictly confined to floral patterns but is used here for cane designs other than the complicated mosaic designs of the first century BCE to the first century CE.

Mosiac glass

Used in different ways by different authors. It is used here to refer to figures and patterns made up from sections of glass rod. Examples are chequer-board patters, human faces, hieroglyphs and so on. However it could be used to refer to conglomerate or millefiori glass.

Network former

An inorganic oxide which can be used to form viteous materials. For ancient glass this is silicon dioxide (silica). However, silica hasa melting point of 1710C, far beyond the range of ancient glass makers, and so requires a network modifier to allow its use in glass making.

Network modifier

A substance added to the network former in order to enhance its working properties, usually to lower its melting temparature. For ancient glass, this is usually natron or plant ash. Alkali and silica together yield a glass which is water soluble, and to overcome this problem lime is usually added to the mixture.

Rod

Used here to mean an elongated piece of glass which has been poured or pulled from a crucible and/or rolled to make a roughly cylindrical rod. Thin pieces are known as canes, though the two may be used interchangably.

Seed

Name given by glass makers to bubbles left in the glass where gases have not been able to escape before the mass solidified. In modern processes the temparatures are high enough to allow the gases to escape, but anciently this was a problem and, despite the use of fritting as a first stage in Egyptian glass making, some bubbles may still remain.

Shank

The ring part of a finger ring. This may not be a comple circle but rather a U-shape, the bezel closing the circle to make a complete ring.

Skeuomorph

Representation of one material or form in another, for example painted decoration resembling ropes or pottery shaped and textured as baskets.

Stones

Lumps of unmelted raw material which, in modern glass making, settle out of the mass of molten glass during manufacture. Ancient Egyptian glass makers could not achieve sufficiently high temperatures for this settling process to take place and hence used a two-stage process, beginning with fritting.